Drifting and relief valve.



H. F. RIPKEN.

DRIFTINGAND RELIEF VALVE.

APPLICATIGN FILED Jun 10. [9!6.

1 ,272,7 1 8. Patented July 16, 191s.

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UNITED STATES PATENT OFFICE HUGO F. RIPKEN, OF MINNEAPOLIS, MINNESOTA,ASSIGNOR 01 ONE-HALF TO CHARLES A. MOCULLOCH, 0F MINNEAPOLIS, MINNESOTA.

DRIF'IING AND RELIEF VALVE.

Specification of Letters Patent.

Patented J nly 16, 1918.

Application filed July 10, 1916. Serial No. 108,328.

To all whom it may concern:

Be it known that I, HUGO F. RIPKEN, a citizen of the United States,residing at Minneapolis, in the county of Hennepin and State ofMinnesota, have invented certain new and useful Improvements in Driftingand Relief Valves, of which the following is a specification.

My invention relates to improvements in drifting and relief valves forreciprocating steam engines, and especially for those employed inrailway locomotives.

It will be understood that when ,in the ordinary operation of the enginethe supply of steam to the cylinder and steam chest is cut off by theclosing of the throttle valve, the engine will drift for some timebefore it actually comes to rest. In thus drifting the piston willcontinue to move back and forth and as no live steam enters behind thepiston a artial vacuum will be formed at that olnt. This wilt cause aninrush of cold all into the cylin der through the cylinder cocks. andalso as soon as the valve piston in the steam chest has uncovered, thecylinder port to the exhaust on that side, an inrush of smoke, cinders,and gases of combustion from the smoke box through the exhaust nozzle.This is objectionable because the cold air cools the cylinder walls andsteam chest and causes condensation of the steam, and the smoke,cinders, and gases of combustion are destructive of the lubrication ofthe cylinder.

It is the object of this invention to overcome these objections bproviding an improved drifting or relie valve that will antomaticallyand instantly operate to admit a sufficient amount of boiler steam tothe valves and cylinder while the engine is drifting even.at very lowspeed and with the main throttle'valve closed to revent this partialvacuum being formed m the cylinder, and which will also automaticallyclose and'shut ofi' the steam when the engine comes to rest, so thatthere will be no escape or waste of steam through the drifting valvewhen the steam is not needed to prevent a partial vacuum forming indrifting.

With these objects in view I have constructed a valve wherein thecylinder com pression or back pressure upon. the piston, a positiveforce existing only while the engin is in motion, is utilized to furnishthe motive power for operating the valve to open it, and steam enteringfrom the boiler to furnish the power to close it after the back pressurehas ceased owing to the stoppage of the engine and wherein the valve isa ported piston valve, so that no boiler pressure will be exerted u onit in opposition to the pressure from t e cylinder until the piston hasbeen moved far enough to uncover the live steam port, so that the valvewill be opened whenever the cylinder pressure is sufficient to overcomethe weight or inertia of the piston itself, as will always be the casewhen the engine is drifting, even when it is at the slowest s eed andwith the longest cutofl' obtainab e in locomotive service. Moreparticularly the invention consists in the construction, combination,and arrangement of parts hereinafter described and claimed.

In the accompanying drawings showing an embodiment of the invention,

Figure 1 is a vertical longitudinal section through the middle of thecylinder and steam chest of a reciprocating engine with my improvedvalve in elevation, and v Fig. 2 is a, vertical section through themiddle of the valve alone.

In the drawings A represents the cylinder of a reciprocating engine, Bthe piston working therein, and C the steam chest in which works a.valve piston D, all of usual ty ie.

he drifting valve which is the subject of this invention comprises acylindrical casing or cage 2, shown in elevation in Fig. 1 and ,invertical section in Fig; 2, the interior of which is open tocommunication with one end of the interior of the cylinder throu h themedium of a ipe 3 which leadsfrom t e bottom of the va ve easing into aduct 4 extending around the bushm at one end of the steam chest to thecylinder port 5 on that side of the piston B. The com ressed air orsteam in that end of the cylin er can thus ass through the duct 4 andpipe 3 into tlie valve casing below the valve. Another pipe 6 leads fromthe top of the valve casing and has communication with the steam chamber7 of the steam chest.

Working within the valve casing 2 is a sliding valve piston 8 closed atthe bottom and havin an upwardly projectin sleeve extension 1 The upperportion of t e valve piston is somewhat larger in diameter than a withcircumferentia the lower portion and is formed with a shoulder 9 whichseats against a cooperating shoulder 10 on the inside of the casing whenthe valve is not in operation. Just beneath the shoulder the sleeveextension of the valve piston is formed with a circumferential port 11in position to communicate with a circumferential port 12 in the casingwhen the valve piston is moved up. The port 12 is in communication witha live steam inlet conduit or pipe 13 which leads from the boiler (notshown) or other source of steam supply. The orts 11 and 12 are guardedfrom the acci ental passage of steam into the cage by means of packingrings M.

In order to prevent the hammering of the valve piston 8 in the casingand also to reduce the bottom area of the piston sulficiently to allowthe steam pressure from the steam chest entering above it to keep thevalve piston on its seat while the main throttle valve is open and theengine is working, the valve is provided with a centrally dependingplunger 15 of much less diameter than the diameter of the iston and thisplunger works within a das pot 16 carried by the cage 2 a suitabledistance below the valve seat 10. The plunger is shown formed grooves tocatch drippings of oil and condensed steam for lubrication purposes, butthis is no part of my invention. I

The operation of the valve is as follows: When the ressure in the steamchamber of the steam c est falls owing to the closing of the throttlevalve, the compression in the forward end of the cylinder, resultingfrom the continued movement of the piston after the valve in the steamchest has closed the cylinder port to the exhaust outlet, will force thesteam in the cylinder out throu h the ducts 4 and 3 into the lower partof t e valve cage 2 below the valve piston 8. This will throw the valvepiston up and bring the circumferential valve port 11 in the sleeve 17into communication with the port 12, so that the live steam in the pipe13 will pass into the sleeve chamber on the upper side of the valvepiston 8. From this chamher it will pass through the pi e 6 to the steamchest and thence throng the usual channels into thecylinder therebypreventin the formation bf a partial vacuum in the c inder when thesteam supply is cut off by t e closin of the throttle valve. The valvepiston will remain in this position with the ports open to allowthe'steam from the pipe 13 to enter the steam chest and cylinder, untilthe engine comes to rest and the piston no longer causes cylindercompression in the pipe 3 of valve casing 2. When the cylindercompression thus ceases the ressure of steam in the sleeve chamber of te valve iston will force the valve piston down upon its seat, therebyclosing the port .12 and shutbe extremely sensitive to cylindercompression, because the upward travel of the piston will not be opposedby the counter-pressure of live steam from the boiler until the lateralports in the piston sleeve and steam conduit have come into registrationso as to allow the live steam to enter the valve casing. And when thelive steam inlet port is constructed so as completely to encircle thepiston sleeve as here shown, the pressure. of the live steam against thesleeve will be exerted equally upon all sides thereof, so as to hold itin balance without .crowdin it against the casing, thereby avoidingriction with the casing wall.

\Vhile I prefer to use the particular valve structure shown in thedrawings it will be understood that I do not limit myself to thisparticular form but mean to include all modifications thereof which comewithin the principle of the invention as defined in the claims. It willalso be understood that the duct 3 from the valve casing may beconnected with the cylinder directly or indirectly in any convenientway, the only essential being that it be constructed and connected so asto serve as a means of communication between the cylinder and thedrifting valve when the cylinder port to exhaust is closed.

It is to be understood that such changes and rearrangements of parts maybe resorted to as fall within the scope of the appended claims.

I claim as my invention:

1. In a reciprocating engine, the combination with the cylinder andsteam chest, of a drifting valve comprising a valve casing open tocommunication wlth the cylinder at one end and the steam chest at theother end and having intermediately a lateral inlet port for live steam,and a pressure actuated valve piston having a projecting extension normaly closi said liver-steam inlet ort but adapted, w on the piston is moveby the rewure in the cylinder after themain supp y of steam thereto hasbeen shut oil and the engine is drifting, to slide over and uncover saidlive steam inlet, said valve having means of communication between thecasing inlet and the steam chest when said inlet port is uncovered,whereby to allow live steam to enter the valve casing beyond the pistonand pass to the steam chest for the purpose set forth.

2. In a reciprocating en 'ne, the combination with the cylinder an steamchest, of a balanced drifting valve comprising a valve casing open tocommunication with the cg'linder at one end and the steam chest atengine is drifting, will come into registmt e other end and havingintermediately a tion with the live steam inlet port in theeascircumferential inlet port for live steam, ing and allow live steamto enter the portion and a valve piston having-a projectin sleeve of thevalve casing beyond the piston and 15 extension normally covering saidin et port pass into the steam chest.

so as to prevent the live steamfrom entering In testimony whereof Iaflix my signature the valve easing, said sleeve extension bein inpresence of two witnesses.

formed with a circun'lferential port, whic HUGO F. RIPKEN. port, whenthe piston is moved. by. the pres- Witnesses:

sure in the cylinder after the main su ply BEATRICE BROWN,

of steam thereto has been shut ofl and the H. SwANsoN.

